Do you think the NSA had a little say via Gavin in preparing the new code being introduced as XT?  Maybe this is their way of getting the core devs who can't be 'turned' out of the way.  Mike has been in favor of 'blacklisting' - another tool popular with NSA.  I suspect there is a little sneaky bit of code slipped into the XT package that doesn't raise red flags.  Maybe that is what this blocksize thing is really about.